Elastomeric air pump

ABSTRACT

An air pump formed of a resilient elastomeric material bondable about the perimeter of an opening provided in a plastic inflatable bladder, has a self-supporting spherical dome portion and a generally planar base portion. An inlet flapper type valve is integrally formed in a wall of the dome and an outlet check valve extends through an opening in the base for supplying air into the plastic bladder accomplished by alternately compressing and releasing the dome. The underside of the base includes projections disposed about the outlet valve to hold the bladder wall clear of the outlet valve. The base may also include a tail portion which extends laterally of the dome with an exhaust valve affixed thereto for deflating the bladder.

BACKGROUND OF THE INVENTION

This invention relates to pumps associated with air inflatable bladdersand, more particularly, to such pumps as are formed of a resilientelastomeric material.

Inflatable objects, such as air cushions, mattresses and liners forathletic shoes usually are inflated by discrete pumps, such as thebellows pump disclosed in U.S. Pat. No. 2,686,006 to Hasselguist whichis connected by a tube 30 to a check valve affixed to the inflatablebladder.

U.S. Pat. No. 2,698,028 to Lee shows a self-contained pump disclosedwholly within an inflatable cushion.

U.S. Pat. No. 3,583,008 to Edwards discloses a bulb-shaped,self-contained pump 36 connected to each of the inflatable compartmentsof an air mattress. The bulb pump relies upon a U-shaped spring and acoil spring 54 to expand the bulb after it has been compressed in eachstroke of the pump.

Bulb-type pumps have also been used to inflate air cushion liners forathletic shoes and, in general, these have included a rubber bulb withan inlet valve extending outwardly from one side thereof and an outletneck extending from the opposite side of the bulb. A plastic tube isfitted into the neck of the bulb and a check valve is disposed in avalve housing molded onto the liner. An exhaust valve is separatelyconnected to the liner to deflate the liner when desired.

It is the principal object of this invention to provide an elastomericpump and self-contained valve construction for an inflatable bladder ofsimple and compact construction while, at the same time, being reliablein operation.

It is another object of this invention to provide a pump of the abovetype which, because of its simple construction, lends itself to ease ofassembly on an inflatable bladder.

It is a further object of this invention to provide a pump of a lowprofile especially adapted to be used in inflatable body supportapplications, such as inflatable athletic shoe liners and back supportbelts, where compactness, comfort, durability and reliability areessential.

The above and other objects and advantages of this invention will bemore readily apparent from the following description read in conjunctionwith the accompanying drawings in which:

FIG. 1 is an exploded perspective view of an inflatable article and apump of the type embodying this invention;

FIG. 2 is cross-sectional, elevational view of the pump of FIG. 1 inassembled relation on the inflatable article;

FIG. 3 is a sectional view taken along line 3--3 of FIG. 2 and

FIG. 4 is an overall perspective view of the pump disposed on aninflatable liner.

The pump embodying this invention is shown generally at 6 and comprisesan open-sided dome member 8 and a base member 10. The pump is adapted tobe fused, heat-sealed or bonded about the periphery of an opening 12provided through one sheet 14 of an inflatable bladder 18, the otherside of the bladder being provided by a sheet 16. The two sheets areadapted to be heat-sealed about the outer edges, as indicated at 17 inFIG. 4, to form the inflatable bladder 18.

The dome member 8 of the pump is preferably of hemisphericalconfiguration, open at its planar end, shown in FIGS. 1 and 2, facingdownward toward the base member 10. The dome member 8 may beinjection-molded of a resilient elastomeric material, such as apolyurethane polymer. Integrally molded into the dome member, is aninlet, check valve, preferably of the flapper type 20. An outwardlyextending peripheral flange 24 is formed about the open end of the dome,as at 25 in FIG. 2. The flapper valve 20, formed integrally within asegmental recess 22 in the sidewall of the dome, is slitted about itslower end portion so that this portion will be free to swing in and out,as depicted in FIG. 2. When the dome 8 is compressed, valve 20 will"close" and will "open" as the dome expands to draw in ambient airthrough the flapper valve 20.

Base 10 comprises a generally planar sheet of the same elastomer as isused to form the dome 8 and it includes an upstanding circular rim 26.The rim 26 has an outer diameter which is somewhat smaller than theinner diameter of the base of the dome 8. With this arrangement, thedome and base can be quickly and easily fitted together and can besimultaneously heat-sealed together and about the margins of opening 12in the superimposed plastic sheet material 14 which, in part, forms theinflatable bladder 18. In accordance with this invention, the base 10may either have a circular overall shape which corresponds with that ofthe lower edge flange 24 of the dome 8 or, preferably, it may have agenerally keyhole shape, as best illustrated in FIG. 1. As shown, thelarger end of the base 10 corresponds generally to the shape of thecircular cutout, or opening 12, and a tail portion 39 extends radially,or laterally from the circular portion and its outer end corresponds tothe shape of a second circular cutout 12'. The tail portion 39 providesmeans for integrally combining with the pump, a push-button type exhaustvalve 40 for deflating the bladder.

Outlet valve 30 extends from pumping chamber 27 through the panel 10within the area defined by the upstanding rim 26. The valve 30 may beany suitable type of check valve which provides one-way air flow fromthe pumping chamber 27 defined by the dome 8 and base 10 to theinflatable bladder, as at 18. The valve 30 may be a flexible, "duckbill" type fitted into a raised boss, or rim portion 28, of the basepanel 10. The boss 28 includes an internal bore therethrough with anannular slot 29 adapted to securely retain an upper flange portion ofthe valve 30 in place within the base portion of the pump 6. The outlettip of the valve 30 is flexible and slitted, as at 32, to permit one-wayair flow from chamber 27.

A plurality of arcuate projections 34 extend from the lower surface ofthe panel 10 a somewhat greater distance than does the outlet tip of thevalve 30. This construction ensures that the opposed wall portion of thebladder 18 will not interfere with, or inhibit, the air flow through thevalve 30 into the inflatable bladder 18.

An elastomer suitable in practicing this invention is one such aspolyurethane having a Shore A durometer hardness of 60-75 whereby thedome will have sufficient rebound resilience to perform the necessarypumping function. The top portion of the dome 8 may be about 0.030" inthickness and the lower wall portions, 0.035"-0.060". The thickness ofthe flange portions 24 and base member 10 may each be approximately0.030" and the elastomer is preferably heat-sealable.

The exhaust valve 40 includes a stem 42 with an actuator flange orbutton at its upper end and a generally spherical closure member 43disposed at its lower end. The stem is biased, "normally closed", by acoil spring 46 and is movable within opening 47 provided through a boss48 molded as an integral part of the tail portion 39 of the base 10.Depending projections 44 are disposed about the valve head 43 to preventthe sheet 16 of the bladder 18 from interfering with the operation ofthe valve 40 in much the same manner as the projections 34 served toensure proper operation of the valve 30.

Among the advantages of this combination of a pump and valveconstruction, are its adaptability for ease of assembly on an inflatablebladder, such as 18. With the valves 30 and 40 simply fitted into thebores 29 and 47 provided through the base 10, only two parts thereafterneed to be handled, i.e., dome 8 and base 10. The dome 8 may be fittedonto the base 10 using the locating rim 26 to facilitate this step. Thepump sub-assembly may then be affixed to the bladder 18 which, asillustrated in FIG. 1, is accomplished by fitting the dome 8 throughhole 12 in the sheet 14 with the peripheral edges of the flange 24aligned with margins of the opening 12 in sheet 14 (FIG. 2). At the sametime, the exhaust valve 40 would be fitted through opening 12' in sheet14 and the sub-assembly may then be heat-sealed, fused, welded, orotherwise bonded about the peripheral flange 24 and simultaneously aboutthe peripheral edge of the exhaust valve 40. As a consequence, the domeand the base of the pump are integrated or united and the air pump,exhaust valve and sheet 14 of the bladder are also simultaneously joinedtogether in a unitary structure.

OPERATION

In operation, it is only necessary to manually, by using the finger orthumb, depress and release the reslient elastomeric dome 8 a sufficientnumber of pulsations until the bladder 18 is properly inflated. Duringthis pumping action, the inlet valve 20 "closes" on a pressure strokewhen air from chamber 27 is pumped through the check valve 30 and"opens" on the exhaust stroke when the dome 8 reexpands to itsuncompressed condition. When desired to deflate the bladder, such as inan athletic shoe liner, the user need merely depress valve 40 to exhaustthe air from the chamber of the bladder.

Having thus described my invention, what is claimed is:
 1. Air pump forinflatable bladder comprising an open ended dome member ofself-supporting, semi-spherical configuration and a generally planarbase member, the dome member being hermetically sealed to the basemember about a peripheral edge portion of the open end thereof to form adome-shaped unitary pumping chamber, the dome member being formed of aresiliently flexible, elastomeric material such that the dome isinherently compressible and expansible, an inlet check valve of the flaptype formed by a portion of the elastomeric material of the spericaldome member and an outlet check valve extending through the base memberfor providing communication between the unitary pumping chamber and theinterior of the inflatable bladder.
 2. Air pump for inflatable bladder,as set forth in claim 1, in which said elastomer is a urethane polymer.3. Air pump for inflatable bladder, as set forth in claim 1, in whichsaid elastomer has Shore A durometer hardness in the range of 60-75. 4.Air pump for inflatable bladder, as set forth in claim 1, in which saidbase member is an elastomer and the dome and base member are heat-sealedtogether to form the pumping chamber of the pump.
 5. Air pump forinflatable bladder, as set forth in claim 4, in which said dome has aplanar opening at its major diameter, said bladder includes an openingthrough one wall portion thereof corresponding to the dome opening, saiddome and base members being heat-sealed together and to said bladderabout the peripheral edges of said bladder opening.
 6. Air pump forinflatable bladder, as set forth in claim 5, in which said base includesat least one projection disposed adjacent said outlet check valve, whichextends beyond the end of said check valve to prevent the bladder fromblocking air flow through said outlet valve.
 7. Air pump for inflatablebladder, as set forth in claim 5, in which said dome includes anoutwardly extending peripheral flange about the edge defining its majordiameter and said base member includes, on its inner surface, anupstanding annular peripheral rim adapted to interfit within the openedge of the dome.
 8. Air pump for inflatable bladder as set forth inclaim 1 in which, said base member includes a tail portion extendingoutwardly of the dome and an exhaust valve extending through the tailportion of the base member for use in deflating said bladder.
 9. Airpump for inflatable bladder, as set forth in claim 8, and in which saidoutlet valve and exhaust valve are each surrounded, at least in part, byprojections extending outwardly from the lower surface of the basemember a greater distance that the corresponding dimensions of theoutlet valve and exhaust valve.